Antenna structure and wireless communication device using same

ABSTRACT

An antenna structure includes a metallic member, a first feed portion, a first ground portion and a second ground portion. The metallic member includes a front frame, a backboard, and a side frame. The side frame defines a slot. The front frame defines a first gap and a second gap communicating with the slot and extending across the front frame. A portion of the front frame between the first gap and the second gap forms a first radiating section. Current enters the first radiating section from the first feed portion and flows through the first radiating section and towards the first gap and the second gap to generate radiation signals in a first frequency band and a second frequency band. The frequencies of the first frequency band are higher than the frequencies of the second frequency band. A wireless communication device using the antenna structure is provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. patent application Ser. No.62/365,341 filed on Jul. 21, 2016, and claims priority to Chinese PatentApplication No. 201710565900.4 filed on Jul. 12, 2017, the contents ofwhich are incorporated by reference herein.

FIELD

The subject matter herein generally relates to an antenna structure anda wireless communication device using the antenna structure.

BACKGROUND

Metal housings, for example, metallic backboards, are widely used forwireless communication devices, such as mobile phones or personaldigital assistants (PDAs). Antennas are also important components inwireless communication devices for receiving and transmitting wirelesssignals at different frequencies, such as wireless signals in Long TermEvolution Advanced (LTE-A) frequency bands. However, when the antenna islocated in the metal housing, the antenna signals are often shielded bythe metal housing. This can degrade the operation of the wirelesscommunication device. Additionally, the metallic backboard generallydefines slots or/and gaps thereon, which will affect an integrity and anaesthetic of the metallic backboard.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present disclosure will now be described, by wayof example only, with reference to the attached figures.

FIG. 1 is an isometric view of a first exemplary embodiment of awireless communication device using a first exemplary antenna structure.

FIG. 2 is another isometric view of the wireless communication device ofFIG. 1.

FIG. 3 is a detail view of the antenna structure of FIG. 1.

FIG. 4 is a circuit diagram of a switching circuit of the antennastructure of FIG. 1.

FIG. 5 is a current path distribution graph when the antenna structureof FIG. 1 is in operation.

FIG. 6 is a return loss (RL) graph when the antenna structure of FIG. 1is in operation.

FIG. 7 is a return loss (RL) graph when the antenna structure of FIG. 1operates at a WiFi 2.4G mode and a WiFi 5G mode.

FIG. 8 is a radiating efficiency graph when the antenna structure ofFIG. 1 operates at a LTE-A low frequency mode, a LTE-A middle frequencymode, a LTE-A high frequency mode, and a GPS mode.

FIG. 9 is a radiating efficiency graph when the antenna structure ofFIG. 1 operates at the WiFi 2.4G mode and the WiFi 5G mode.

FIG. 10 is an isometric view of a second exemplary embodiment of awireless communication device using a second exemplary antennastructure.

FIG. 11 is detailed view of the antenna structure of the wirelesscommunication device of FIG. 10.

FIG. 12 is a detail view of the antenna structure of FIG. 10.

FIG. 13 is a current path distribution graph when the antenna structureof FIG. 10 is in operation.

FIG. 14 is a circuit diagram of a switching circuit of the antennastructure of FIG. 10.

FIG. 15 is a scattering parameter graph when the antenna structure ofFIG. 10 operates at a LTE-A low frequency mode, a LTE-A middle frequencymode, a LTE-A high frequency mode, and a GPS mode.

FIG. 16 is a scattering parameter graph when the antenna structure ofFIG. 10 operates at a WiFi 2.4G mode and a WiFi 5G mode.

FIG. 17 is a radiating efficiency graph when the antenna structure ofFIG. 10 operates at the LTE-A low frequency mode, the LTE-A middlefrequency mode, the LTE-A high frequency mode, and the GPS mode.

FIG. 18 is a radiating efficiency graph when the antenna structure ofFIG. 10 operates at the WiFi 2.4G mode and the WiFi 5G mode.

FIG. 19 is an isometric view of a third exemplary embodiment of thewireless communication device using a third exemplary antenna structure.

FIG. 20 is another isometric view of the wireless communication deviceof FIG. 19.

FIG. 21 is a detailed view of the antenna structure of the wirelesscommunication device of FIG. 20.

FIG. 22 is a current path distribution graph when the antenna structureof FIG. 19 is in operation.

FIG. 23 is a circuit diagram of a matching circuit of the antennastructure of FIG. 19.

FIG. 24 is a circuit diagram of a switching circuit of the antennastructure of FIG. 19.

FIG. 25 is a scattering parameter graph when the antenna structure ofFIG. 19 is working.

FIG. 26 is a radiating efficiency graph when the antenna structure ofFIG. 19 is working.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein can be practiced without these specificdetails. In other instances, methods, procedures, and components havenot been described in detail so as not to obscure the related relevantfeature being described. Also, the description is not to be consideredas limiting the scope of the embodiments described herein. The drawingsare not necessarily to scale and the proportions of certain parts havebeen exaggerated to better illustrate details and features of thepresent disclosure.

Several definitions that apply throughout this disclosure will now bepresented.

The term “substantially” is defined to be essentially conforming to theparticular dimension, shape, or other feature that the term modifies,such that the component need not be exact. For example, substantiallycylindrical means that the object resembles a cylinder, but can have oneor more deviations from a true cylinder. The term “comprising,” whenutilized, means “including, but not necessarily limited to”; itspecifically indicates open-ended inclusion or membership in theso-described combination, group, series and the like.

The present disclosure is described in relation to an antenna structureand a wireless communication device using same.

FIG. 1 illustrates a first embodiment of a wireless communication device200 using a first exemplary antenna structure 100. The wirelesscommunication device 200 can be a mobile phone or a personal digitalassistant, for example. The antenna structure 100 can receive or sendwireless signals.

Per FIGS. 1-3, the antenna structure 100 includes a metallic member 11,a first feed portion 12, a second feed portion 13, a third feed portion14, a radiating portion 15, a second radiating portion 16, a fourth feedportion 17, a third radiating portion 18, a fifth feed portion 19, and aswitching circuit 20 (shown in FIG. 4).

The metallic member 11 can be a metal housing of the wirelesscommunication device 200. In this exemplary embodiment, the metallicmember 11 is a frame structure and includes a front frame 111, abackboard 112, and a side frame 113 as shown in FIG. 1. The front frame111, the backboard 112, and the side frame 113 can be integral with eachother. The front frame 111, the backboard 112, and the side frame 113cooperatively form the metal housing of the wireless communicationdevice 200. The front frame 111 defines an opening (not shown) thereon.The wireless communication device 200 includes a display 201. Thedisplay 201 is received in the opening. The display 201 has a displaysurface. The display surface is exposed at the opening and is positionedparallel to the backboard 112.

The backboard 112 is positioned opposite to the front frame 111. Thebackboard 112 is coupled to the side frame 113, and there is no gapbetween the backboard 112 and the side frame 113. The backboard 112 isan integrally formed metallic sheet. Except the holes 204, 205 forexposing dual backside cameras 202 and a receiver 203, the backboard 112does not define any other slot, break line, and/or gap as shown in FIG.2. The backboard 112 serves as a ground of the antenna structure 100.

The side frame 113 is positioned between the front frame 111 and thebackboard 112. The side frame 113 is positioned around a periphery ofthe front frame 111 and a periphery of the backboard 112. The side frame113 forms a receiving space 114 together with the display 201, the frontframe 111, and the backboard 112. The receiving space 114 can receive aprint circuit board 210, a processing unit (not shown), or otherelectronic components or modules. In this exemplary embodiment, theelectronic components or modules at least include the dual backsidecameras 202, the receiver 203, and a front camera 207. The dual backsidecameras 202, the receiver 203, and the front camera 207 are arranged onthe print circuit board 210 and spaced apart from each other.

Referring to FIG. 1, the side frame 113 includes a top portion 115, afirst side portion 116, and a second side portion 117. The top portion115 connects the front frame 111 and the backboard 112. The first sideportion 116 is spaced apart from and parallel to the second side portion117. The top portion 115 has first and second ends. The first sideportion 116 is connected to the first end of the first frame 111 and thesecond side portion 117 is connected to the second end of the topportion 115. The first side portion 116 connects the front frame 111 andthe backboard 112. The second side portion 117 also connects the frontframe 111 and the backboard 112. The side frame 113 defines a slot 118.In this exemplary embodiment, the slot 118 is defined at the top portion115 and extends to the first side portion 116 and the second sideportion 117. In other exemplary embodiments, the slot 118 can only bedefined at the top portion 115 and does not extend to any one of thefirst side portion 116 and the second side portion 117. In otherexemplary embodiments, the slot 118 can be defined only at the topportion 115, but not extending to any of the first side portion 116 andthe second side portion 117. In other exemplary embodiments, the slot118 can be defined at the top portion 115 and extends to one of thefirst side portion 116 and the second side portion 117.

Referring to FIG. 3, the front frame 111 includes a top arm (notlabeled) corresponding to the top portion 115 and two side arms (notlabeled) corresponding to the first side portion 116 and the second sideportion 117. The front frame 111 defines a first gap 1112 and a secondgap 1114 at the top arm and a third gap 1116 and a four gap 1118 at thetwo side arms, respectively. The third gap 1116 and the four gap 1118are defined on opposite ends of the slot 118. The gaps 1112, 1114, 1116,1118 are in air communication with the slot 118 and extend across thefront frame 111. The front frame 111 is divided by the gaps 1112, 1114,1116, 1118 into three portions, which are a first radiating section 22,a second radiating section 24, and a third radiating section 26. In thisexemplary embodiment, the first gap 1112 and the second gap 1114 aredefined on the top arm of the front frame 111. The first gap 1112 andthe second gap 1114 are respectively disposed adjacent to corners onopposite ends of the top arm, the first radiating section 22 is formedbetween the first gap 1112 and the second gap 1114. The second radiatingsection 24 is formed between the first gap 1112 and the third gap 1116,extends from the top arm to a side arm of the front frame 111, andcrosses an arc corner. The third radiating section 26 is formed betweenthe second gap 1114 and the fourth gap 1118, extends from the top arm toanother arm of the front frame 111, and crosses another arc corner. Inthis exemplary embodiment, the slot 118 and the gaps 1112, 1114, 1116,1118 are filled with insulating material, for example, plastic, rubber,glass, wood, ceramic, or the like, thereby isolating the first radiatingsection 22, the second radiating section 24, the third radiating section26, and the backboard 112.

In this exemplary embodiment, except for the slot 118 and the gaps 1112,1114, 1116, 1118, an upper half portion of the front frame 111 and theside frame 113 does not define any other slot, break line, and/or gap.That is, there are only the gaps 1112, 1114, 1116, 1118 defined on theupper half portion of the front frame 111.

Referring to FIG. 3, the first feed portion 12 is electrically connectedto an end the first radiating section 22 adjacent to the first gap 1112through a matching circuit (not shown), thus the first feed portion 12feeds in current for the first radiating section 22. In this exemplaryembodiment, after the current is fed into the first feed portion 12, thecurrent flows towards the first gap 1112 and the second gap 1114 alongthe first radiating section 22. Thus, the first radiating section 22 isdivided into a short portion A1 and a long portion A2 by a connectingpoint of the first feed portion 12. The short portion A1 extends towardsthe first gap 1112 and the long portion A2 extends towards the secondgap 1114 from the connecting point of the first feed portion 12. In thisexemplary embodiment, the connecting point of the first feed portion 12is not positioned at a middle portion of the first radiating section 22.The long portion A2 is longer than the short portion A1. The shortportion A1 activates a first mode to generate radiation signals in afirst frequency band, the long portion A2 activates a second mode togenerate radiation signals in a second frequency band. In this exemplaryembodiment, the first mode is a LTE-A (Long Term Evolution Advanced)middle frequency operation mode, the first frequency band is a frequencyband of about 1805-2170 MHz. The second mode is a LTE-A low frequencyoperation mode, the second frequency band is a frequency band of about703-960 MHz.

The first radiating section 22 is connected to a first ground portion 27and a second ground portion 28. The first ground portion 27 and thesecond ground portion 28 are arranged on two sides of the first feedportion 12. The first ground portion 27 and the second ground portion 28are both substantially L-shaped arms.

The first radiating portion 15 is substantially L-shaped, one arm of thefirst radiating portion 15 is parallel to the first ground portion 27and connects to the a third ground portion 152, the other arm of thefirst radiating portion 15 is parallel to the first radiating section22. The first radiating portion 15 obtains coupling current from thefirst radiating section 22 to activate the first frequency band. In thisexemplary embodiment, the first radiating section 22, the first feedportion 12, the first ground portion 27, the second ground portion 28,the first radiating portion 15, and the third ground portion 152cooperatively form a first diversity antenna. The first diversityantenna resonates radiation signals of the LTE-A low frequency operationmode and the LTE-A middle frequency operation mode.

The second feed portion 13 is substantially L-shaped, one end of thesecond feed portion 13 connects to the second radiating section 24 andis adjacent to the third gap 1116. The second feed portion 13 feeds incurrent into the second radiating section 24 to cooperatively activate athird mode to generate radiation signals in a third frequency band. Inthis exemplary embodiment, the third mode is a GPS mode, the thirdfrequency band is a frequency band of about 1575 MHz. The secondradiating section 24 and the second feed portion 13 cooperatively form aGPS antenna resonating radiation signals covering GPS frequency band.

The third feed portion 14 is substantially L-shaped, one end of thethird feed portion 14 connects to the third radiating section 26 and isadjacent to the four gap 1118. The third feed portion 14 feeds incurrent into the third radiating section 26 to cooperatively activate afourth mode to generate radiation signals in a fourth frequency band. Inthis exemplary embodiment, the fourth mode is a WiFi 2.4G mode, thefourth frequency band is a frequency band of about 2400-2484 MHz. Thethird radiating section 26 and the third feed portion 14 cooperativelyform a WiFi 2.4G antenna resonating radiation signals covering WiFi 2.4Gfrequency band.

The second radiating portion 16 is spaced apart from the first radiatingsection 22, the second radiating section 24, the second feed portion 13,and the front camera 207. The second radiating portion 16 is received ina space surrounded by the first radiating section 22, the secondradiating section 24, the second feed portion 13, and the front camera207. The second radiating portion 16 includes a first arm 161, a secondarm 162, a third arm 163, a fourth arm 164, and a fifth arm 165, whichare substantially straight arms. The second radiating portion 16connects to the fourth feed portion 17 and a fourth ground portion 166.In this exemplary embodiment, the fourth feed portion 17 and the fourthground portion 166 are both substantially straight arms and parallel toeach other. The first arm 161 is perpendicularly connected between thefourth feed portion 17 and the fourth ground portion 166. The second arm162 is perpendicularly connected between the first arm 161 and the thirdarm 163. The first arm 161 and the third arm 163 are parallel and extendfrom two opposite ends of the second arm 162. The second arm 162 and thefourth arm 164 are parallel and extend from two opposite ends of thethird arm 163. The fourth arm 164 is perpendicularly connected betweenthe third arm 163 and the fifth arm 165. The third arm 163 and the fiftharm 165 are parallel and extend from two opposite ends of the fourth arm164. A length of the fifth arm 165 is greater than a length of the thirdarm 163, and a length of the fourth arm 164 is greater than a length ofthe second arm 162. The third arm 163 is parallel to and spaced apartfrom the second radiating section 24, the fourth arm 164 is parallel toand spaced apart from the short portion A1, and the fourth feed portion17 is parallel to and spaced apart from the second feed portion 13. Thefourth feed portion 17 feeds current into the second radiating portion16 to cooperatively activate a fifth mode to generate radiation signalsin a fifth frequency band. In this exemplary embodiment, the fifth modeis a LTE-A high frequency mode, the fifth frequency band is a frequencyband of about 2300-2690 MHz. The second radiating portion 16, the fourthfeed portion 17, and the fourth ground portion 166 cooperatively form asecond diversity antenna resonating radiation signals covering highfrequency band.

The third radiating portion 18 is spaced apart from the dual backsidecameras 202, the third radiating section 26, and the second gap 1114.The third radiating portion 18 is received in a space surrounded by thedual backside cameras 202 and the third radiating section 26. The thirdradiating portion 18 is a substantially straight arm and is parallel tothe third radiating section 26. The third radiating portion 18 connectsto the fifth feed portion 19 and a fifth ground portion 182. In thisexemplary embodiment, the fifth feed portion 19 and the fifth groundportion 182 are both substantially straight arms and parallel to eachother. The fifth feed portion 19 feeds current into the third radiatingportion 18 to cooperatively activate a sixth mode to generate radiationsignals in a sixth frequency band. In this exemplary embodiment, thesixth mode is a WiFi 5G mode, the sixth frequency band is a frequencyband of about 5150-5850 MHz. The third radiating portion 18, the fifthfeed portion 19, and the fifth ground portion 182 cooperatively form aWiFi 5G antenna resonating radiation signals covering the WiFi 5Gfrequency band.

Per FIG. 4, the switching circuit 20 is arranged on the circuit board210. One end of the switching circuit 20 is electrically connected tothe second ground portion 28, the other end connects to the ground. Thebackboard 112 serves as the ground of the antenna structure 100.Perhaps, a middle frame or a shielding mask (not shown) also may servesas the ground of the antenna structure 100, the middle frame can be ashielding mask for shielding electromagnetic interference arranged onthe display 201 facing the backboard 112. The shielding mask or themiddle frame can be made of metal material. The shielding mask or themiddle frame may connect to the backboard 112 to form a greater groundfor the antenna structure 100. In summary, each ground portion directlyor indirectly connects to the ground.

The switching circuit 20 includes a switching unit 222 and a pluralityof switching elements 224. The switching unit 222 is electricallyconnected to the second ground portion 28. The switching elements 224can be an inductor, a capacitor, or a combination of the inductor andthe capacitor. The switching elements 224 are connected in parallel toeach other. One end of each switching element 224 is electricallyconnected to the switching unit 222. The other end of each switchingelement 224 is electrically connected to the backboard 112. Throughcontrolling the switching unit 222, the long portion A2 can be switchedto connect with different switching elements 224. Since each switchingelement 224 has a different impedance, an operating frequency band ofthe long portion A2 can be adjusted through switching the switching unit222, for example, the frequency band of the second mode of the longportion A2 can be offset towards a lower frequency or towards a higherfrequency (relative to each other).

In this exemplary embodiment, to obtain preferred antennacharacteristics, a width of the slot 118 can be 3.83 millimeter, that isa distance between the backboard 112 and the first radiating section 22,the second radiating section 24, and the third radiating section 26 canbe 3.83 millimeter, thus to improve antenna characteristic for theradiating sections by being spaced apart from the backboard 112. A widthof each of the gaps 1112, 1114, 1116, 1118 can be 2 millimeter, whichmay further improve antenna characteristic for the radiating sections.

Referring to FIG. 3, in this exemplary embodiment, the second radiatingportion 16 is spaced apart from a side of the front camera 207. Thefirst ground portion 27 is spaced apart from another side of the frontcamera 207. The second ground portion 28 is spaced apart from andbetween the dual backside cameras 202 and the receiver 203. The thirdradiating portion 18 is spaced apart from a side of the dual backsidecameras 202.

Per FIG. 5, when the current enters the first radiating section 22 fromthe first feed portion 12, the current flows towards two direction, onedirection flows through the short portion A1 and towards the first gap1112 (please see a path P1), meanwhile the current is coupled to thefirst radiating portion 15 and flows opposite to the path P1 (please seea path P2). The current paths P1 and P2 cooperatively activate the LTE-Amiddle frequency mode. The current in the first radiating section 22,the other direction flows through the long portion A2 and towards thesecond gap 1114 (please see a path P3), thus, activating the LTE-A lowfrequency mode. Since the antenna structure 100 includes the switchingcircuit 20, the LTE-A low frequency mode of the long portion A2 can beswitched through the switching circuit 20. When the current enters thesecond radiating section 24 from the second feed portion 13, the currentflows through the second radiating section 24 and towards the first gap1112 (please see a path P4), thus, activating the GPS mode. When thecurrent enters the third radiating section 26 from the third feedportion 14, the current flows through the third radiating section 26 andtowards the second gap 1114 (please see a path P5), thus, activating theWiFi 2.4G mode. When the current enters the second radiating portion 16from the fourth feed portion 17, the current flows through the secondradiating portion 16 along its extending direction (please see a pathP6), thus, activating the LTE-A high frequency mode. When the currententers the third radiating portion 18 from the fifth feed portion 19,the current flows through the third radiating portion 18 along itsextending direction (please see a path P7), thus, activating the WiFi 5Gmode.

FIG. 6 illustrates a return loss (RL) graph of the first diversityantenna, the second diversity antenna, and the GPS antenna when working.Curves S1, S2, S3 illustrate return losses when the long portion A2operates at the LTE-A low frequency band. Curves S1, S2, S3 havedifferent shapes due to the switching circuit 20 adjusting the frequencyband. Curve S4 illustrates a return loss when the second radiatingportion 16 operates at the LTE-A high frequency band (2300-2690 MHz).Curve S5 illustrates a return loss when the second radiating section 24operates at the GPS frequency band (1575 MHz).

FIG. 7 illustrates a return loss (RL) graph of the WiFi 2.4G antenna andthe WiFi 5G antenna when working. Curve S6 illustrates a return losswhen the third radiating section 26 operates at the WiFi 2.4G frequencyband (2400-2484 MHz). Curve S7 illustrates a return loss when the thirdradiating portion 18 operates at the WiFi 5G frequency band (5150-5850MHz).

FIG. 8 illustrates a radiating efficiency graph of the first diversityantenna, the second diversity antenna, and the GPS antenna when working.Curves S81, S82, S83 illustrate radiating efficiencies when the longportion A2 operates at the LTE-A low frequency band. Curves S81, S82,S83 have different shapes due to the switching circuit 20 adjusting thefrequency band. Curve S84 illustrates a radiating efficiency when thesecond radiating portion 16 operates at the LTE-A middle frequency band(1805-2170 MHz). Curve S85 illustrates a radiating efficiency when thesecond radiating section 24 operates at the GPS frequency band (1575MHz).

FIG. 9 illustrates a radiating efficiency graph of the WiFi 2.4G antennaand the WiFi 5G antenna when working. Curve S87 illustrates a radiatingefficiency when the third radiating section 26 operates at the WiFi 2.4Gfrequency band (2400-2484 MHz). Curve S88 illustrates a radiatingefficiency when the third radiating portion 18 operates at the WiFi 5Gfrequency band (5150-5850 MHz).

Per FIGS. 5 to 8, the antenna structure 100 can work at a low frequencyband, for example, LTE-A band 28 (703-803MHz), LTE-A Band 5 (869-894MHz), and LTE-A Band 8 (925-926 MHz), at a middle frequency band(1805-2170 MHz), and at a high frequency band (2300-2690 MHz). Theantenna structure 100 can also work at the GPS frequency band (1575MHz), WiFi 2.4G frequency band (2244-2484 MHz) and the WiFi 5G frequencyband (5150-5850 MHz). That is, the antenna structure 100 can work at thelow frequency band, the middle frequency band, and the high frequencyband. When the antenna structure 100 operates at these frequency bands,a working frequency satisfies a design of the antenna and also has agood radiating efficiency.

The antenna structure 100 includes the metallic member 11 and thebackboard 112. The metallic member 11 defines the slot on the side frame113 and the gaps on the front frame 111. The backboard 112 is anintegrally formed metallic sheet without other slot, break line, and/orgap, which maintains integrity and aesthetics.

FIG. 10 illustrates a second embodiment of a wireless communicationdevice 400 using a second exemplary antenna structure 300. The wirelesscommunication device 400 can be a mobile phone or a personal digitalassistant, for example. The antenna structure 300 can receive or sendwireless signals.

Per FIG. 11, the antenna structure 300 includes a metallic member 31, afirst feed portion 32, a first ground portion 33, a second groundportion 34, a second feed portion 35, a third ground portion 36, aradiating portion 37, a third feed portion 38, a fourth ground portion39, a first switching circuit 46 (shown in FIG. 14), and a secondswitching circuit 47 (shown in FIG. 14).

The metallic member 31 can be a metal housing of the wirelesscommunication device 400. In this exemplary embodiment, the metallicmember 31 is a frame structure and includes a front frame 311, abackboard 312, and a side frame 313 as shown in FIG. 10. The front frame311, the backboard 312, and the side frame 313 can be integral with eachother. The front frame 311, the backboard 312, and the side frame 313cooperatively form the metal housing of the wireless communicationdevice 400. The front frame 311 defines an opening (not shown) thereon.The wireless communication device 400 includes a display 401. Thedisplay 401 is received in the opening. The display 401 has a displaysurface. The display surface is exposed at the opening and is positionedparallel to the backboard 312.

The backboard 312 is positioned opposite to the front frame 311. Thebackboard 312 is coupled to the side frame 313, and there is no gapbetween the backboard 312 and the side frame 313. The backboard 312 isan integrally formed metallic sheet. Except the holes 404, 405 forexposing dual backside cameras 402 and a receiver 403, the backboard 312does not define any other slot, break line, and/or gap. The backboard312 serves as a ground of the antenna structure 300 as shown in FIG. 12.

The side frame 313 is positioned between the front frame 311 and thebackboard 312. The side frame 313 is positioned around a periphery ofthe front frame 311 and a periphery of the backboard 312. The side frame313 forms a receiving space 314 together with the display 401, the frontframe 311, and the backboard 312. The receiving space 314 can receive aprint circuit board 410, a processing unit (not shown), or otherelectronic components or modules. In this exemplary embodiment, theelectronic components or modules at least include the dual backsidecameras 402, the receiver 403, and a front camera 407. The dual backsidecameras 402, the receiver 403, and the front camera 407 are arranged onthe print circuit board 410 and spaced apart from each other.

Referring to FIG. 1, the side frame 313 includes a top portion 315, afirst side portion 316, and a second side portion 317. The top portion315 connects the front frame 311 and the backboard 312. The first sideportion 316 is spaced apart from and parallel to the second side portion317. The top portion 315 has first and second ends. The first sideportion 316 is connected to the first end of the first frame 311 and thesecond side portion 317 is connected to the second end of the topportion 315. The first side portion 316 connects the front frame 311 andthe backboard 312. The second side portion 317 also connects the frontframe 311 and the backboard 312. The side frame 313 defines a slot 318.In this exemplary embodiment, the slot 318 is defined at the top portion315 and extends to the first side portion 316 and the second sideportion 317. In other exemplary embodiments, the slot 318 can only bedefined at the top portion 315 and does not extend to any one of thefirst side portion 316 and the second side portion 317. In otherexemplary embodiments, the slot 318 can be defined only at the topportion 315, but not extending to any of the first side portion 316 andthe second side portion 317. In other exemplary embodiments, the slot318 can be defined at the top portion 315 and extends to one of thefirst side portion 316 and the second side portion 317.

Referring to FIG. 11, the front frame 311 includes a top arm (notlabeled) corresponding to the top portion 315 and two side arms (notlabeled) corresponding to the first side portion 316 and the second sideportion 317. The front frame 311 defines a first gap 3112 and a thirdgap 3116 at the two side arms, respectively, and a second gap 3114 atthe top arm. The first gap 3112 and the third gap 3116 are defined onopposite ends of the slot 318. The gaps 3112, 3114, 3116 are in aircommunication with the slot 318 and extend across the front frame 311.The front frame 311 is divided by the gaps 3112, 3114, 3116 into threeportions, which are a first radiating section 42 and a second radiatingsection 44. In this exemplary embodiment, the second gap 3114 is definedon the top arm of the front frame 311. The first gap 3112 and the secondgap 3114 are respectively disposed adjacent to corners on an end of thetop arm. The first radiating section 42 is formed between the second gap3114 and the third gap 3116, extends from the top arm to a side arm ofthe front frame 311, and crosses an arc corner (not shown). The secondradiating section 44 is formed between the first gap 3112 and the secondgap 3116, extends from the top arm to another side arm of the frontframe 311, and crosses another arc corner (not shown). A length of thefirst radiating section 42 is greater than the second radiating section44. In this exemplary embodiment, the slot 318 and the gaps 3112, 3114,3116 are filled with insulating material, for example, plastic, rubber,glass, wood, ceramic, or the like, thereby isolating the first radiatingsection 42, the second radiating section 44, and the backboard 312.

In this exemplary embodiment, except for the slot 318 and the gaps 3112,3114, 3116, an upper half portion of the front frame 311 and the sideframe 313 does not define any other slot, break line, and/or gap. Thatis, there are only the gaps 3112, 3114, 3116 defined on the upper halfportion of the front frame 311.

Referring to FIG. 11, one end of the first feed portion 32 iselectrically connected to an end the first radiating section 42 and isadjacent to the second gap 3114, the other end of the first feed portion32 is electrically connected to a feeding source, which may feed currentinto the first radiating section 42. In this exemplary embodiment, afterthe current is fed into the first feed portion 32, the current flowstowards the second gap 3114 and the third gap 3116 along the firstradiating section 42. Thus, the first radiating section 42 is dividedinto a short portion B1 and a long portion B2 by a connecting point ofthe first feed portion 32. The short portion B1 extends towards thesecond gap 3114 and the long portion B2 extends towards the third gap3116 from the connecting point of the first feed portion 32. In thisexemplary embodiment, the connecting point of the first feed portion 32is not positioned at a middle portion of the first radiating section 42.The long portion B2 is longer than the short portion B1.

The first radiating section 42 connects to the first ground portion 33and the second ground portion 34. The first ground portion 33 and thesecond ground portion 34 are on opposite sides of the first feed portion32. Per FIGS. 11 and 13, the first ground portion 33 connects to theshort portion B1, the second ground portion 34 connects to the longportion B2. The first feed portion 32 includes a first arm 322, a secondarm 324, and a third arm 326. The second arm 324 is substantiallyU-shaped and substantially perpendicularly connects to the first arm 322and the third arm 326 on two ends. The first arm 322 and the second arm324 are spaced apart from the first radiating section 42, the third arm326 connects to the second arm 324 and the first radiating section 42.The first ground portion 33 and the second ground portion 34 are bothsubstantially L-shaped.

The short portion B1 activates a first mode to generate radiationsignals in a first frequency band, the long portion B2 activates asecond mode to generate radiation signals in a second frequency band,the long portion B2 and the short portion B1 cooperatively activates athird mode to generate radiation signals in a third frequency band. Inthis exemplary embodiment, the first mode is a LTE-A (Long TermEvolution Advanced) middle frequency operation mode, the first frequencyband is a frequency band of about 1575-2170 MHz. The second mode is aLTE-A low frequency operation mode, the second frequency band is afrequency band of about 703-960 MHz. The third mode is a GPS mode, thethird frequency band is a frequency band of about 1575 MHz. The firstradiating section 42, the first feed portion 32, the first groundportion 33, and second ground portion cooperatively form a firstdiversity/GPS antenna, which resonating radiation signals in the LTE-Alow frequency mode, the LTE-A middle frequency mode, and the GPS mode.

The first switching circuit 46 and the second switching circuit 47 areboth arranged on the circuit board 410. Per FIG. 14, one end of thefirst switching circuit 46 connects to the first ground portion 33, theother end connects to a ground; one end of the second switching circuit47 connects to the second ground portion 34, the other end connects tothe ground. The backboard 312 serves as the ground of the antennastructure 300. Perhaps, a middle frame or a shielding mask (not shown)also may serves as the ground of the antenna structure 300, the middleframe can be a shielding mask for shielding electromagnetic interferencearranged on the display 401 facing the backboard 312. The shielding maskor the middle frame can be made of metal material. The shielding mask orthe middle frame may connect to the backboard 312 to form a greaterground for the antenna structure 300. In summary, each ground portiondirectly or indirectly connects to the ground.

The first switching circuit 46 includes a switching unit 462 and aplurality of switching elements 464. The switching unit 462 iselectrically connected to the first ground portion 33. The switchingelements 464 can be an inductor, a capacitor, or a combination of theinductor and the capacitor. The switching elements 464 are connected inparallel to each other. One end of each switching element 464 iselectrically connected to the switching unit 462. The other end of eachswitching element 464 is electrically connected to the backboard 312.Through controlling the switching unit 462, the short portion B1 can beswitched to connect with different switching elements 464. Since eachswitching element 464 has a different impedance, an operating frequencyband of the short portion B1 can be adjusted through switching theswitching unit 462, for example, the frequency band of the first mode ofthe short portion B1 can be offset towards a lower frequency or towardsa higher frequency (relative to each other). The second switchingcircuit 47 is substantially similar to the first switching circuit 46and configured to offset the frequency band of the second mode of thelong portion B2. The LTE-A low frequency band mode may cover 703-804MHz, 824-894 MHz, and 880-960 MHz by offsetting the impedance of thesecond switching circuit 47.

One end of the second feed portion 35 connects to the second radiatingsection 44 and is adjacent to the first gap 3112. The second feedportion 35 includes a fourth arm 352, a fifth arm 354, a sixth arm 356,and a seventh arm 358. The third ground portion 36 is substantiallystraight arm and connected to the ground. The fourth arm 352 is spacedapart from and parallel to the third ground portion 36. The fifth arm354 is connected between the fourth arm 352 and the third ground portion36. The sixth arm 356 is substantially U-shaped and connects to thefifth arm 354 and the seventh arm 358 on opposite ends, the end of thesixth arm 356 connecting the fifth arm 354 further connects to thefourth arm 352, the fifth arm 354 extends along the sixth arm 356extending direction. The fourth arm 352, the fifth arm 354, the sixtharm 356, and the third ground portion 36 are spaced apart from thesecond radiating section 44, the seventh arm 358 is connected betweenthe sixth arm 356 and the second radiating section 44. The second feedportion 35 feeds current into the second radiating section 44 tocooperatively activate a fourth mode to generate radiation signals in afourth frequency band. In this exemplary embodiment, the fourth mode isa LTE-A high frequency mode, the fourth frequency band is a frequencyband of about 2300-2690 MHz. Additionally, the fourth mode furtherincludes a fifth mode, the fifth mode is a WiFi 2.4G mode, the fourthfrequency band includes a fifth frequency band, the fifth frequency bandis a WiFi 2.4G frequency band, the WiFi 2.4G frequency band is afrequency band of about 2400-2484 MHz. The second radiating section 44,the second feed portion 35, and the third ground portion 36cooperatively form a second diversity/WiFi 2.4G antenna resonatingradiation signals covering the LTE-A high frequency band and the WiFi2.4G frequency band.

The radiating portion 37 is positioned among and spaced apart from thedual backside cameras 402, the long portion B2, and the third gap 3116.The radiating portion 37, the third feed portion 38, and the fourthground portion 39 are substantially straight. The third feed portion 38is parallel to and spaced apart from the fourth ground portion 39. Theradiating portion 37 connects to a same side of the third feed portion38 and the fourth ground portion 39 and extends towards the top arm ofthe front frame 311. The fourth ground portion 39 connects to theground. The third feed portion 38 feeds current into the radiatingportion 37 to cooperatively activate a sixth mode to generate radiationsignals in a sixth frequency band. In this exemplary embodiment, thesixth mode is a WiFi 5G mode, the sixth frequency band is a frequencyband of about 5150-5850 MHz. The radiating portion 37, the third feedportion 38, and the fourth ground portion 39 cooperatively form a WiFi5G antenna resonating radiation signals covering the WiFi 5G frequencyband.

In this exemplary embodiment, to obtain preferred antennacharacteristics, a width of the slot 318 can be 3.83 millimeter, that isa distance between the backboard 312 and the first radiating section 42and the second radiating section 44 can be 3.83 millimeter, the width ofthe slot 318 can be adjusted in a range of about 3-4.5 millimeter, thusto improve antenna characteristic for the radiating sections by beingspaced apart from the backboard 312. A width of each of the gaps 3112,3114, 3116 can be 2 millimeter and can be adjusted in a range of about1.5-2.5 millimeter, which may further improve antenna characteristic forthe radiating sections.

Per FIG. 13, when the current enters the first radiating section 42 fromthe first feed portion 32, the current flows towards two direction, onedirection flows through the short portion B1 and towards the second gap3114 and the first ground portion 33 (please see a path P1), thus,activating the LTE-A middle frequency mode. When the current enters thefirst radiating section 42 from the first feed portion 32, anotherdirection flows through the long portion B2 and towards the third gap3116 (please see a path P2), thus, activating the LTE-A low frequencymode. Meanwhile, when the current enters the first radiating section 42from the first feed portion 32 and flows both through the short portionB1 towards the second gap 3114 and through the long portion B2 towardsthe third gap 3116 and the second ground portion 34 (please see a pathP3), thus, activating the GPS mode. When the current enters the secondradiating section 44 from the second feed portion 35, the current flowsthrough the second radiating section 44 and towards the second gap 3114(please see a path P4), thus, activating the LTE-A high frequency modeand the WiFi 2.4G mode. When the current enters the radiating portion 37from the third feed portion 38, the current flows thought the radiatingportion 37 along its extending direction (please see a path P5), thus,activating the WiFi 5G mode.

FIG. 15 illustrates a scattering parameter graph of the firstdiversity/GPS antenna and the second diversity/WiFi 2.4G antenna whenworking. Curves S1, S2, S3 illustrate scattering parameters of the firstdiversity/GPS antenna and the second diversity/WiFi 2.4G antenna thoughthe adjust of the first switching circuit 46 and the second switchingcircuit 47 and operates at the LTE-A low frequency band (703-960 MHz),the GPS frequency band (1575 MHz), and the LTE-A middle frequency band(1575-2170 MHz). Curve S4 illustrates a scattering parameter of thefirst diversity/GPS antenna and the second diversity/WiFi 2.4G antennaoperates at the WiFi 2.4G frequency band (2400-2484 MHz).

FIG. 16 illustrates a scattering parameter graph of the seconddiversity/WiFi 2.4G antenna and the WiFi 5G antenna when working. CurveS5 in FIG. 16 is the same as the curve S4 of FIG. 15. Curve S6illustrates a scattering parameter of the radiating portion 37 operatesat the WiFi 5G frequency band (5150-5850 MHz).

FIG. 17 illustrates a radiating efficiency graph of the firstdiversity/GPS antenna and the second diversity/WiFi 2.4G antenna whenworking. Curves S81, S82, S83 illustrate radiating efficiencies of thefirst diversity/GPS antenna and the second diversity/WiFi 2.4G antennaoperates at different frequency bands though the adjust of the firstswitching circuit 46 and the second switching circuit 47.

FIG. 18 illustrates a radiating efficiency graph of the seconddiversity/WiFi 2.4G antenna and the WiFi 5G antenna when working. CurveS87 illustrates a radiating efficiency of the second radiating section44 operates at the WiFi 2.4G frequency band (2400-2484 MHz). Curve S88illustrates a radiating efficiency of the radiating portion 37 operatesat the WiFi 5G frequency band (5150-5850 MHz).

Per FIGS. 15 to 18, the first diversity/GPS antenna, the seconddiversity/WiFi 2.4G antenna, and the WiFi 5G antenna can work at a lowfrequency band, for example, LTE-A low frequency band (703-960 MHz), ata middle frequency band (1575-2170 MHz), and at a high frequency band(2300-2690 MHz). The antenna structure 300 can also work at the GPSfrequency band (1575 MHz), WiFi 2.4G frequency band (2044-2484 MHz) andthe WiFi 5G frequency band (5150-5850 MHz). That is, the antennastructure 300 can work at the low frequency band, the middle frequencyband, and the high frequency band. When the antenna structure 300operates at these frequency bands, a working frequency satisfies adesign of the antenna and also has a good radiating efficiency.

The antenna structure 300 includes the metallic member 31 and thebackboard 312. The metallic member 31 defines the slot on the side frame313 and the gaps on the front frame 311. The backboard 312 is anintegrally formed metallic sheet without other slot, break line, and/orgap, which maintains integrity and aesthetics.

FIG. 19 illustrates a third embodiment of a wireless communicationdevice 600 using a third exemplary antenna structure 500. The wirelesscommunication device 600 can be a mobile phone or a personal digitalassistant, for example. The antenna structure 500 can receive or sendwireless signals.

Per FIG. 19, FIG. 20 and FIG. 21, the antenna structure 500 includes ametallic member 51, a first feed portion 52, a first ground portion 53,a second ground portion 54, an extending section 55, a radiating portion56, a second feed portion 57, a third ground portion 58, a matchingcircuit 64 (shown in FIG. 23), a first switching circuit 66, and asecond switching circuit 67 (shown in FIG. 24).

The metallic member 51 can be a metal housing of the wirelesscommunication device 600. In this exemplary embodiment, the metallicmember 51 is a frame structure and includes a front frame 511, abackboard 512, and a side frame 513. The front frame 511, the backboard512, and the side frame 513 can be integral with each other. The frontframe 511, the backboard 512, and the side frame 513 cooperatively formthe metal housing of the wireless communication device 600. The frontframe 511 defines an opening (not shown) thereon. The wirelesscommunication device 600 includes a display 601. The display 601 isreceived in the opening. The display 601 has a display surface. Thedisplay surface is exposed at the opening and is positioned parallel tothe backboard 512.

The backboard 512 is positioned opposite to the front frame 511. Thebackboard 512 is coupled to the side frame 513, and there is no gapbetween the backboard 512 and the side frame 513. The backboard 512 isan integrally formed metallic sheet. Except the holes for exposing dualbackside cameras and a receiver, the backboard 512 does not define anyother slot, break line, and/or gap. The backboard 512 serves as a groundof the antenna structure 500.

The side frame 513 is positioned between the front frame 511 and thebackboard 512. The side frame 513 is positioned around a periphery ofthe front frame 511 and a periphery of the backboard 512. The side frame513 forms a receiving space 514 together with the display 601, the frontframe 511, and the backboard 512. The receiving space 514 can receive aprint circuit board 610, a processing unit, or other electroniccomponents or modules. In this exemplary embodiment, the electroniccomponents or modules at least include an audio jack 602 and a USBconnector 603. The audio jack 602 and the USB connector 603 are arrangedon the print circuit board 610 and spaced apart from each other.

The side frame 513 includes a bottom portion 515, a first side portion516, and a second side portion 517. The bottom portion 515 connects thefront frame 511 and the backboard 512. The first side portion 516 isspaced apart from and parallel to the second side portion 517. Thebottom portion 515 has first and second ends. The first side portion 516is connected to the first end of the first frame 311 and the second sideportion 517 is connected to the second end of the bottom portion 515.The first side portion 516 connects the front frame 511 and thebackboard 512. The second side portion 517 also connects the front frame511 and the backboard 512. The side frame 513 defines a slot 518. Inthis exemplary embodiment, the slot 518 is defined at the bottom portion515 and extends to the first side portion 516 and the second sideportion 517. In other exemplary embodiments, the slot 518 can only bedefined at the bottom portion 515 and does not extend to any one of thefirst side portion 516 and the second side portion 517. In otherexemplary embodiments, the slot 518 can be defined only at the bottomportion 515, but not extending to any of the first side portion 516 andthe second side portion 517. In other exemplary embodiments, the slot518 can be defined at the bottom portion 515 and extends to one of thefirst side portion 516 and the second side portion 517.

The front frame 511 defines a first gap 5112 and a second gap 5114 attwo side arms, respectively. The first gap 5112 and the second gap 5114are defined on opposite ends of the slot 518. The gaps 5112, 5114 are inair communication with the slot 518 and extend across the front frame511. The front frame 511 between the first gap 5112 and the second gap5114 forms a radiating section 62. In this exemplary embodiment, theradiating section 62 extends from the top arm to two side arms of thefront frame 511 and crosses two arc corners. In this exemplaryembodiment, the slot 518 and the gaps 5112, 5114 are filled withinsulating material, for example, plastic, rubber, glass, wood, ceramic,or the like, thereby isolating the radiating section 62 and thebackboard 512.

The slot 518 defines two holes 5182, 5183 corresponding to the audiojack 602 and the USB connector 603, respectively. Thus, the audio jack602 and the USB connector 603 may partially expose from the wirelesscommunication device 400 for connecting an earphone and a USB device,respectively.

In this exemplary embodiment, except for the slot 518 and the gaps 5112,5114, an lower half portion of the front frame 511 and the side frame513 does not define any other slot, break line, and/or gap. That is,there are only the gaps 5112, 5114 defined on the lower half portion ofthe front frame 511.

One end of the first feed portion 52 connects to the radiating section62, the other end electronically connects to a feed source 59 throughthe matching circuit 64 (shown in FIG. 23). Thus, the feed source 59feeds current into the radiating section 62 through the matching circuit64 and the first feed portion 52. In this exemplary embodiment, afterthe current is fed into the first feed portion 52, the current flowstowards the first gap 5112 and the second gap 5114 along the radiatingsection 62. Thus, the radiating section 62 is divided into a shortportion C1 and a long portion C2. The short portion C1 extends towardsthe first gap 5112 and the long portion C2 extends towards the secondgap 5114 from the connecting point of the first feed portion 52. In thisexemplary embodiment, the connecting point of the first feed portion 52is not positioned at a middle portion of the radiating section 62. Thelong portion C2 is longer than the short portion C1.

The radiating section 62 connects to the first ground portion 53 and thesecond ground portion 54. The first ground portion 53 and the secondground portion 54 are positioned on opposite sides of the first feedportion 52. The first ground portion 53 connects to the short portion C1and the second ground portion 54 connects to the long portion C2. Thefirst ground portion 53 and the second ground portion 54 are bothsubstantially L-shaped. The first ground portion 53 is spaced adjacentto the audio jack 602. The first ground portion 53 includes a first arm532, a second arm 534, and a third arm 536. The second arm 532 issubstantially U-shaped and connects to the first arm 532 and the thirdarm 536 on opposite ends. The second arm 534 surrounds the hole 5182.The second arm 534 and the third arm 536 are spaced apart from theradiating section 62. The first arm 532 connects to the second arm 534and the short portion C1. The third arm 536 connects to the backboard512, that is connects to the ground.

The extending section 55 is received in the receiving space 514. Theextending section 55 extends from an end of the long portion C2 and isadjacent to the second gap 5114 along a direction towards the first gap5112, and extends passing a position of the second ground portion 54.The extending section 55 is parallel to and spaced apart from the bottomarm of the front frame 511.

The short portion C1 and the first ground portion 53 activate a firstmode to generate radiation signals in a first frequency band, the longportion C2 activates a second mode to generate radiation signals in asecond frequency band, the long portion C2 and the extending section 55cooperatively activate third mode to generate radiation signals in athird frequency band. In this exemplary embodiment, the first mode is aLTE-A (Long Term Evolution Advanced) middle frequency operation mode,the first frequency band is a frequency band of about 1710-1990 MHz. Thesecond mode is a LTE-A low frequency operation mode, the secondfrequency band is a frequency band of about 703-960 MHz. The third modeis another LTE-A middle frequency operation mode, the third frequencyband is a frequency band of about 2110-2170 MHz.

Per FIG. 23, the matching circuit 64 is electrically connected betweenthe first feed portion 52 and the feed source 59. The matching circuit64 and the feed source 59 are both arranged on the printed circuit board610. The matching circuit 64 includes a first impedance element 641, asecond impedance element 642, a third impedance element 643, a fourthimpedance element 644, and a fifth impedance element 645. The firstimpedance element 641, the second impedance element 642, and the thirdimpedance element 643 are electrically connected in series. The firstimpedance element 641 is electrically connected to the feed source 59,the third impedance element 643 is electrically connected to the firstfeed portion 52. One end of the fourth impedance element 644 iselectrically connected between the first impedance element 641 and thesecond impedance element 642, the other end connects to the ground. Oneend of the fifth impedance element 645 is electrically connected betweenthe second impedance element 642 and the third impedance element 643,the other end connects to the ground. The matching circuit 64 mayincrease a bandwidth of the LTE-A middle frequency band for theradiating section 62. In this exemplary embodiment, the first impedanceelement 641 can be an inductor with 9.8 nanohenry (nH), the secondimpedance element 642 can be an inductor with 1.8 nH, the thirdimpedance element 643 can be a capacitor with 0.8 picofarad (pF), thefourth impedance element 644 can be a capacitor with 0.87 pF, and thefifth impedance element 645 can be a capacitor with 0.3 pF.

Per FIG. 24, one end of the first switching circuit 66 connects to thesecond ground portion 54, the other end connects to the ground. Thebackboard 512 serves as the ground of the antenna structure 500.Perhaps, a middle frame or a shielding mask (not shown) also may servesas the ground of the antenna structure 500, the middle frame can be ashielding mask for shielding electromagnetic interference arranged onthe display 601 facing the backboard 512. The shielding mask or themiddle frame can be made of metal material. The shielding mask or themiddle frame may connect to the backboard 512 to form a greater groundfor the antenna structure 500. In summary, each ground portion directlyor indirectly connects to the ground.

The first switching circuit 66 includes a switching unit 662 and aplurality of switching elements 664. The switching unit 662 iselectrically connected to the second ground portion 54. The switchingelements 664 can be an inductor, a capacitor, or a combination of theinductor and the capacitor. The switching elements 664 are connected inparallel to each other. One end of each switching element 664 iselectrically connected to the switching unit 662. The other end of eachswitching element 664 is electrically connected to the backboard 512.Through controlling the switching unit 662, the long portion C2 can beswitched to connect with different switching elements 664. Since eachswitching element 664 has a different impedance, an operating frequencyband of the long portion C2 can be adjusted through switching theswitching unit 662, for example, the frequency band of the second modeof the long portion C2 can be offset towards a lower frequency ortowards a higher frequency (relative to each other). The LTE-A lowfrequency mode may cover frequencies bands of about 703-804 MHz, 824-894MHz, and 880-960 MHz by adjusting the impedance of the first switchingcircuit 66. The second switching circuit 67 is substantially similar tothe first switching circuit 66. One end of the second switching circuit67 electrically connects to the third ground portion 58, the other endconnects to the ground. The first frequency band may be adjusted byadjusting a connecting position of the first ground portion 53 and theshort portion C1, and by adjusting a bent length of the first groundportion 53. The third frequency band may be adjusted by adjusting alength of the extending section 55. When the length of the extendingsection 55 increases, the third frequency band decreases; when thelength of the extending section 55 decreases, the third frequency bandincreases.

The radiating portion 56 includes a fourth arm 562, a fifth arm 564, anda sixth arm 566. The fourth arm 562 is substantially perpendicularlyconnected to the backboard 512. The fifth arm 564 is substantiallyperpendicularly connected to an end of the fourth arm 562 away from thebackboard 512 and extends in a same direction with the extendingdirection of the extending section 55. The fifth arm 564 is parallel tothe extending section 55 and extends to above the USB connector 603. Thesixth arm 566 is substantially an L-shaped arm and connects to an end ofthe fifth arm 564 away from the fourth arm 562. The sixth arm 566extends outwardly from the fifth arm 564 and bents towards the fourtharm 562 and is parallel to the fifth arm 564. The second feed portion 57and the third ground portion 58 are both substantially straight arms.The second feed portion 57 is parallel to and spaced apart from thefourth arm 562, and connects to the fifth arm 564. The third groundportion 58 is parallel to and spaced apart from the second feed portion57, and connects to the fifth arm 564. The second feed portion 57 feedscurrent into the radiating portion 56 to cooperatively activate a fourthmode to generate radiation signals in a fourth frequency band. In thisexemplary embodiment, the fourth mode is a LTE-A high frequency mode,the fourth frequency band is a frequency band of about 2300-2690 MHz.

In this exemplary embodiment, to obtain preferred antennacharacteristics, a width of the slot 518 can be 3.9 millimeter, that isa distance between the backboard 512 and the radiating section 62 can be3.9 millimeter, the width of the slot 518 can be adjusted in a range ofabout 3-4.5 millimeter, thus to improve antenna characteristic for theradiating sections by being spaced apart from the backboard 512. A widthof each of the gaps 5112, 5114 can be 2 millimeter and can be adjustedin a range of about 1.5-2.5 millimeter, which may further improveantenna characteristic for the radiating sections. A thickness of thefront frame 511 can be 1.5 millimeter, that is a thickness of the gaps5112, 5114 can be 1.5 millimeter.

Per FIG. 13, when the current enters the radiating section 62 from thefirst feed portion 52, the current flows towards two direction, onedirection flows through the short portion C1 and towards the first gap5112 and the first ground portion 53 (please see a path P1), thus,activating the first mode. When the current enters the radiating section62 from the first feed portion 52, another direction flows through thelong portion C2 and towards the second gap 5114 (please see a path P2),thus, activating the second mode. Meanwhile, when the current enters theradiating section 62 from the first feed portion 52, flows through thelong portion C2 and towards the second gap 5114, and further flowsthrough the extending section 55 (please see a path P3), thus,activating the third mode. When current enters the radiating portion 56from the second feed portion 57, flows through the radiating portion 56along its extending direction and flows through the third ground portion58 (please see a path P4), thus, activating the fourth mode.

FIG. 25 illustrates a scattering parameter graph of the antennastructure 500 when operates at different frequencies bands.

FIG. 26 illustrates a radiating efficiency graph of the antennastructure 500 when operates at different frequency bands.

The antenna structure 500 can work at a low frequency band, for example,LTE-A low frequency band (703-960 MHz), at a middle frequency band(1710-1990 MHz), at another middle frequency band (2110-2170 MHz), andat a high frequency band (2300-2690 MHz), and when the antenna structure500 operates at these frequency bands, a working frequency satisfies adesign of the antenna and also has a good radiating efficiency.

The antenna structure 500 includes the metallic member 51 and thebackboard 512. The metallic member 51 defines the slot on the side frame513 and the gaps on the front frame 511. The backboard 512 is anintegrally formed metallic sheet without other slot, break line, and/orgap, which maintains integrity and aesthetics.

The embodiments shown and described above are only examples. Manydetails are often found in the art such as the other features of theantenna structure and the wireless communication device. Therefore, manysuch details are neither shown nor described. Even though numerouscharacteristics and advantages of the present disclosure have been setforth in the foregoing description, together with details of thestructure and function of the present disclosure, the disclosure isillustrative only, and changes may be made in the details, especially inmatters of shape, size and arrangement of the parts within theprinciples of the present disclosure up to, and including the fullextent established by the broad general meaning of the terms used in theclaims. It will therefore be appreciated that the embodiments describedabove may be modified within the scope of the claims.

What is claimed is:
 1. An antenna structure comprising: a metallicmember, the metallic member comprising a front frame, a backboard, and aside frame, the side frame being between the front frame and thebackboard, the side frame comprising at least a top portion, a firstside portion, and a second side portion, the first side portion and thesecond side portion respectively connected to two ends of the topportion; a first feed portion; a first ground portion; and a secondground portion; wherein the side frame defines a slot, the slot isdefined on at least the top portion; wherein the front frame defines afirst gap and a second gap, the first gap and the second gap are betweentwo opposite ends of the slot, the first gap and the second gapcommunicate with the slot and extend across the front frame; wherein aportion of the front frame between the first gap and the second gapforms a first radiating section, the first feed portion, the firstground portion, and the second ground portion are electrically connectedto the first radiating section, the first feed portion is positionedbetween the first ground portion and the second ground portion; andwherein current enters the first radiating section from the first feedportion, the current flows through the first radiating section andtowards the first gap and the second gap, respectively, to generateradiation signals in a first frequency band and a second frequency band,a frequency of the first frequency band is higher than a frequency ofthe second frequency band.
 2. The antenna structure of claim 1, whereinthe slot and the gaps are all filled with insulating material.
 3. Theantenna structure of claim 1, wherein the slot extends from the topportion to the first side portion and the second side portion of theside frame, the front frame further defines a third gap and a fourthgap, the third gap and the fourth gap are on the two opposite ends ofthe slot.
 4. The antenna structure of claim 3, wherein the first gap,the second gap, the third gap, and the fourth gap separate the firstradiating section, a second radiating section, and a third radiatingsection from the front frame; the second radiating section is formedbetween the first gap and the third gap and extends from the top arm toa side arm of the front frame; the third radiating section is formedbetween the second gap and the fourth gap and extends from the top armto another side arm of the front frame.
 5. The antenna structure ofclaim 4, wherein the first feed portion is electrically connected to anend the first radiating section adjacent to the first gap; the firstradiating section is divided into a short portion towards the first gapand a long portion towards the second gap according to a connectingpoint of the first feed portion; the long portion is longer than theshort portion.
 6. The antenna structure of claim 5, wherein the shortportion activates a first mode to generate radiation signals in thefirst frequency band, the long portion activates a second mode togenerate radiation signals in the second frequency band; the first modeis an LTE-A (Long Term Evolution Advanced) middle frequency operationmode, the first frequency band is a frequency band of about 1805-2170MHz; the second mode is an LTE-A low frequency operation mode, thesecond frequency band is a frequency band of about 703-960 MHz.
 7. Theantenna structure of claim 6, further comprising a switching circuit,wherein the switching circuit includes a switching unit and a pluralityof switching elements, the switching unit is electrically connected tothe second ground portion, the switching elements are connected inparallel to each other; one end of each switching element iselectrically connected to the switching unit, the other end of eachswitching element is electrically connected to a ground; throughcontrolling the switching unit, the long portion is switched to connectwith different switching elements; since each switching element has adifferent impedance, the first frequency band is adjusted throughswitching the switching unit.
 8. The antenna structure of claim 6,further comprising a first radiating portion, wherein the firstradiating portion is substantially L-shaped, one arm of the firstradiating portion is parallel to the first ground portion and connectsto the a third ground portion, another arm of the first radiatingportion is parallel to the first radiating section; the first radiatingportion obtains coupling current from the first radiating section toactivates the first frequency band.
 9. The antenna structure of claim 8,wherein the first radiating section, the first feed portion, the firstground portion, the second ground portion, the first radiating portion,and the third ground portion cooperatively form a first diversityantenna; the first diversity antenna resonates radiation signals of theLTE-A low frequency operation mode and the LTE-A middle frequencyoperation mode.
 10. The antenna structure of claim 5, further comprisinga second feed portion, wherein the second feed portion is L-shaped, oneend of the second feed portion connects to one end of the secondradiating section adjacent to the third gap; the second feed portionfeeds current into the second radiating section to activate a third modeto generate radiation signals in a third frequency band, the third modeis a GPS mode, the third frequency band is a frequency band of about1575 MHz.
 11. The antenna structure of claim 5, further comprising athird feed portion, wherein the third feed portion is L-shaped, one endof the third feed portion connects to one end of the third radiatingsection adjacent to the four gap, the third feed portion feeds currentinto the third radiating section to activate a fourth mode to generateradiation signals in a fourth frequency band, the fourth mode is a WiFi2.4G mode, the fourth frequency band is a frequency band of about2400-2484 MHz.
 12. The antenna structure of claim 5, further comprisinga second radiating portion, a fourth feed portion, and a fourth groundportion, wherein the second radiating portion is spaced apart from thefirst radiating section, the second radiating section, and the secondfeed portion; the second radiating portion includes a first arm, asecond arm, a third arm, a fourth arm, and a fifth arm; the first arm,the second arm, the third arm, the fourth arm, and the fifth arm aresubstantially straight arms; the second radiating portion connects tothe fourth feed portion and the fourth ground portion.
 13. The antennastructure of claim 12, wherein the fourth feed portion and the fourthground portion are both substantially straight arms and parallel to eachother, the first arm is perpendicular connected between the fourth feedportion and the fourth ground portion, the second arm is perpendicularconnected between the first arm and the third arm, the first arm and thethird arm are in parallel and extend oppositely from two ends of thesecond arm, the second arm and the fourth arm are in parallel and extendalong a same direction from two ends of the third arm, the fourth arm isperpendicular connected between the third arm and the fifth arm, thethird arm and the fifth arm are in parallel and extend along a samedirection from two ends of the fourth arm, a length of the fifth arm isgreater than that of the third arm, a length of the fourth arm isgreater than that of the second arm, the third arm is parallel to andspaced apart from the second radiating section, the fourth arm isparallel to and spaced apart from the short portion, the fourth feedportion is parallel to and spaced apart from the second feed portion.14. The antenna structure of claim 12, wherein the fourth feed portionfeeds current into the second radiating portion to activate a fifth modeto generate radiation signals in a fifth frequency band, the fifth modeis an LTE-A high frequency mode, the fifth frequency band is a frequencyband of about 2300-2690 MHz.
 15. The antenna structure of claim 5,further comprising a third radiating portion, a fifth feed portion, anda fifth ground portion, wherein the third radiating portion is arrangedspaced apart from the third radiating section and the second gap, thethird radiating portion is substantially straight arm and parallel tothe third radiating section, the third radiating portion connects to thefifth feed portion and the fifth ground portion, the fifth feed portionand the fifth ground portion are both substantially straight arms andparallel to each other.
 16. The antenna structure of claim 15, whereinthe fifth feed portion feeds current into the third radiating portion toactivate a sixth mode to generate radiation signals in a sixth frequencyband, the sixth mode is a WiFi 5G mode, the sixth frequency band is afrequency band of about 5150-5850 MHz.
 17. The antenna structure ofclaim 1, wherein the backboard is directly connected to the side frameand there is no any gap between the backboard and the side frame, thebackboard is an integral and single metallic sheet, the backboard doesnot define any slot, break line, or gap for dividing the backboard. 18.A wireless communication device, comprising: an antenna structure, theantenna structure comprising: a metallic member, the metallic membercomprising a front frame, a backboard, and a side frame, the side framebeing positioned between the front frame and the backboard, the sideframe comprising at least a top portion, a first side portion, and asecond side portion, the first side portion and the second side portionbeing respectively connected to two ends of the top portion; a firstfeed portion; a first ground portion; and a second ground portion;wherein the side frame defines a slot, the slot is defined on at leastthe top portion; wherein the front frame defines a first gap and asecond gap, the first gap and the second gap are between two oppositeends of the shot, the first gap and the second gap communicate with theslot and extends across the front frame; wherein a portion of the frontframe between the first gap and the second gap forms a first radiatingsection, the first feed portion, the first ground portion, and thesecond ground portion are electrically connected to the first radiatingsection, the first feed portion is positioned between the first groundportion and the second ground portion; and wherein current enters thefirst radiating section from the first feed portion, the current flowsthrough the first radiating section and towards the first gap and thesecond gap, respectively, to generate radiation signals in a firstfrequency band and a second frequency band, a frequency of the firstfrequency band is higher than a frequency of the second frequency band.19. The wireless communication device of claim 18, further comprising adisplay, wherein the front frame, the backboard, and the side framecooperatively form a metal housing of the wireless communication device,the front frame defines an opening, the display is received in theopening, a display surface of the display is exposed at the opening andis positioned parallel to the backboard.
 20. The wireless communicationdevice of claim 18, further comprising dual backside cameras, areceiver, and a front camera, wherein the second radiating portion isspaced apart from a side of the front camera, the first ground portionis spaced apart from another side of the front camera, the second groundportion is spaced apart from and between the dual backside cameras andthe receiver, the third radiating portion is spaced apart from a side ofthe dual backside cameras.